#include<iostream> 
using namespace std;
int main()
{
	int Fage,Sage;
	int arg,col=0;
	for(Fage=27;Fage<99;Fage++)
	{
		Sage=Fage-27;
		int a,b;
		a=Fage/10;b=Fage%10;
		arg=b*10+a;
		if(arg==Sage)
		{
			cout<<"F: "<<Fage
			<<"S: "<<Sage
			<<endl;
			col++;
		}
	}
	
	cout<<col<<endl;
	return 0;
}
